[patriciaruth]

The elevator/tail section failed after take-off due to age/stress degeneration of the polymer used to mold it, the plastics equivalent of metal fatigue.

I do not know whether the pilot made sudden maneuvers after take-off that precipitated the failure of the tail section. If so, it might have been in response to an attempted hijacking or it might have been a practice maneuver without understanding the consequences. Since then pilots have been warned not to practice maneuvers to throw hijackers off their feet due to the stresses they put on the plane.

[cardinal4]

The elevator/tail section failed after take-off due to age/stress degeneration of the polymer used to mold it, the plastics equivalent of metal fatigue.

And it was an arcing fuel pump fuse that ignited fuel vapor in an empty centerline fuel tank on TWA 800.